Engine starter



June 8, 1937. J. A. CHARTER 3.3

' ENGINE STARTER Filed May 29,1956

Patented June 8, 1937 ENGINE STARTER James A. Charter, Chicago, 111., assignor to Charter Drive, 1110., Chicago, 111., a corporation of Illinois Application May 29, 1936, Serial No. 82,428

12 Claims.

This invention relates generally to engine starters and more particularly to starters adapt-' ed for use with internal combustion engines and the like.

It is an important object of the present invention to provide an engine starter of the employing a longitudinally shiftable pinion type on a

drive shaft unit and a yieldable driving connection interposed therebetween wherein the pinion is prevented from rebounding toward the engine gear after said pinion has been shifted to its out or retracted position.

The invention contemplates preventing the rebounding of the driving pinion in a starter of the type wherein a tracker carried by the drive shaft unit moves within the convolutions of a coiled spring shiftable as a unit with said pinion.

It is a further object of the present invention to secure the driving pinion against rebounding without the use of auxiliary braking or holding devices, and to this end I propose to render the tracker and coiled spring mentioned above tionally cooperative after the pinion has fricbeen.

shiftedto its retracted position for preventing the inadvertent movement or rebounding pinion toward the engine gear.

f the More specifically my invention contemplates using the starter elements which form the ing connection between the pinion and the drivdrive shaft unit, as for example the above mentioned spring and tracker, to automatically set up cient frictional resistance as the pinion reaches its limiting position of retraction. To ac combounding of the pinion and at the same time permit the pinion to automatically shift toward the engine gear when the drive shaft unit is subsequently rotated by the starting motor.

wherein Figure 1 is a side elevational view of an engine starter constructed in accordance with the teachings of the present invention and disclosing the driving pinion in its retracted or out tion, the in position of the pinion being cated by dot and dash lines;

posiindi- Figure 2 is a side elevational view of the engine starter, disclosing the pinion shifted to its -or driving position;

Figure 3 is a central longitudinal sectional view taken substantially along the line 33 of Figure 1;

Figure 4 is a transverse sectional view taken substantially along the line 4-4 of Figure 1; 5 and Figure 5 is a fragmentary central sectional view of a slightly modified starter construction employing a coiled spring which normally urges the pinion structure axially of the drive shaft unit.

Referring now to the drawing more in detail, wherein like numerals have been employed to designate similar parts throughout the various figures, it will be seen that one embodiment of my invention contemplates an engine starter, designated generally by the numeral In, which includes a rotary driving structure, designated generally by the numeral l2. This rotary driving structure comprises a driving pinion proper, i 4, and an enlarged sleeve section or drum I6 formed integral with said pinion.

A driving spring structure l8 of a multiple or double strand construction is coupled with the sleeve section [6 through the agency of hook portions 20 diametrically positioned and provided at the free extremities of the spring strands. These hook portions 20 are adapted to be received by complementary recesses 22 formed in the sleeve section l6. Each recess includes an axially extending portion and a circumferentially extending portion to accommodate the complementary hook 26.

The pinion and spring structure just described is mounted upon a drive shaft unit which I have indicated generally by the numeral- 24. This drive shaft unit in the present embodiment includes amotor shaft 26 which connects with a suitable electric starting motor (not shown). The drive shaft unit 24 also includes a sleeve section 28 which is driven with the motor shaft 26 through the agency of a suitable key and key-way cTmstruction 3B, Figure 3. A radially extending actuating member or tracker 32 is carried by the sleeve 28 and extends within the helical way 33 in the spring structure 18. A second sleeve section 34 is drivingly coupled at 35 with the sleeve section 28. This sleeve section 34 provides a support for the pinion sleeve section [6. 0 The sleeve I6 is adapted to shift longitudinally of the sleeve section 34 when the tracker 32 moves within the helical way 33. To prevent longitudinal movement of the sleeve section 28 with respect to the shaft 26, a suitable set screw 36 is provided, which is secured against loosening by means of a resilient ring 38.

From the foregoing it will be apparent that if the starter mechanism just described occupies the position shown in Figure 1 and the drive shaft unit 24 suddenly experiences rotation in a counter-clockwise direction as viewed from the left of Figure 1, due to the activation of the starting motor (not shown), the spring structure E8, together with the pinion structure I4, will be shifted without rotation to the right. This carries the pinion M into mesh with the engine gear 49 to be started. In other words, the tracker 32 in making one complete revolution cooperates with the helical spring 18 so as to shift the pinion [4 from its out position, shown in Figure 1, to its in or meshing position, shown in Figure 2. At this point the tracker engages the closed extremity 42 of the spring l8 and continued rotation of the drive shaft unit causes the pinion M to impart rotation to the gear 48.

As soon as the internal combustion engine ,(not shown) becomes self-actuated, the speed of rotation of the gear 40 exceeds the normal rotative speedof the pinion l4, thereby causing said pinion and the spring structure I8 connected therewith to, experience movement. to the left. As the pinion M and its associated elements approach the limit of its retracting movement, the frictional engagement of the tracker 32with the side of the spring strand positioned immediately to the left of the tracker, Figure 1, is increased. In other words, further continued rotation of the pinion i4 is retarded due to this building up of frictional resistance between the tracker and the spring. This frictional engagement between the tracker and the spring causes a gradual deceleration of the pinion H3, or, in other words, gradually dissipates the kinetic energy stored up within the rotating pinion. Should this kinetic energy be dissipated by causing the pinion movement to be suddenly arrested, as by means of, a fixed abutment, the pinion would experience a rebound which would have a tendency to move it into clashing engagement with the rotating gear 40.

Attention is directed to a lug 44 secured to the inner wall of the pinion sleeve section It. As the pinion is rotated so as to cause it to move to the left. and the lug 44 reaches the position indicated by the dot and dash lines of said lug in Figure 4, it engages the end abutment surface or section of the. sleeve 34 and therefore the tracker 32 and associated spring surface begin to build up an increase in frictional resistance. This building up of frictional resistance continues until the lug 44 reaches the vicinity indicated by the solid line disclosure of the lug in Figure 4'. When the lug reaches this vicinity, the frictional resistance which has been developed is sufficient to completely retard the rotative effect of the pinion and to prevent said pinion from rebounding toward the engine gear 40. To positively prevent building up frictional resistance beyond a desired amount, I provide a shoulder or abutment surface 46 on the sleeve section 34. Thus if there is a :frictional resistance to prevent the free forward movement of the pinion when the starting motor is again activated.

In some instances it may be desirable to employ a coil spring 48, shown in Figure 5. This coil spring serves to insure frictional contact between the companion surfaces of the spring and tracker when the pinion approaches the limit of its rearward or retracting movement. This spring 48 need act only through a limited range of the axial movement of the pinion, namely, the movement experienced by the pinion as it approaches its final position of retraction. To prevent creeping of the pinion toward the starting motor, resulting from vibrations of the vehicle with which the starter may be connected, etc., I provide an annular wire spring 5 3 which resiliently rests within a companion peripheral recess in the sleeve section [6. One extremity of this annular spring 50 is bent inwardly to provide an inwardly extending finger 52. The inner or free extremity of this finger 52 is adapted to be positioned within an annular recess 54 in the sleeve section 34 when thepinion occupies its position of retraction as shown in Figures 1 and 3. The resistance to axial movement to the right set up by the resilient finger 52 is sufficient to prevent inadvertent movement or creeping of the pinion into engagement with the engine gear 40, but is insuificient to prevent the advancement of the pinion, when the starting motor is actuated, to rotate the drive shaft unit 24. In other words, the finger 52 merely serves as an anti-creep device.

. From the foregoing it will be apparent that my invention contemplates an engine starter in which no auxiliary mechanism or actuating elements are required to prevent rebounding of the pinion. I have obviated the necessity of using overrunning clutches or brake mechanisms by so designing my starter as to insure frictional engagement between the actuating parts thereof, as, for example, between the actuating means or member 32 and the spring structure l8, and thereby dissipate the kinetic energy of the pinion during its retraction sufiiciently' gradual to prevent rebounding of the pinion. Thus my invention contemplates a starter which completely obviates the difficulties resulting from the rebounding of the pinion by employing a very simple arrangement of parts which are few in number and durable in construction. Attention is also directed to the fact that I am able to facilitate the cushioning effect of the spring !8 by having the convolutions thereof immediately adjacent the pinion sleeve section l6 positioned close together. Inasmuch as only one complete revolution of the tracker is required to shift the driving pinion between its in? and out positions, the remaining portion of the spring strands are not required to provide a helical way for the tracker. Hence these remaining portions of the spring strands are positioned closer together and thus facilitate the cushioning eflect of the spring. Any tendency for the pinion to clash with the teeth of the engine gear 40 is cushioned by the spring, and furthermore the arrangement of the spring is such as to enhance the yieldable driving characteristics thereof.

Obviously the invention is 'not limited to the arrangement disclosed herein but is capable of other modifications and changes without departing from the spirit and scope of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

, prevent the rebounding thereof.

2.The method of controlling the starting of an internal combustion engine which includes the steps of relatively rotating a pair of frictionally engageable actuating members so as to cause movement of a driving member into operative association with an engine part to be driven, subsequently causing relative rotary movement of said actuating members so as to quickly retract said driving member, and when said driving member approaches a predetermined position of retraction, urging a surface of at least one of said actuating members axially and rotatably toward a surface of the other actuating member to gradually build up frictional resistance between said actuating members whereby to gradually decelerate said engine driving member and prevent the rebounding thereof.

3. The method of controlling the starting of an internal combustion engine which includes the steps of relatively rotating a pair of frictionally engageable actuating members, one of which provides a helical path, so as to cause movement of a driving member into operative association with an engine part to be driven, subsequently causing relative rotary movement of said actuating members so as to quickly retract said driving member, and when said driving member approaches a predetermined position of retraction gradually building-up frictional resistance between said actuating members to gradually decelerate said engine driving member and prevent the rebounding thereof.

4. In an engine starting device, a drive shaft unit,-an engine driving member on said unit adapted for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of saidengine driving member, an abutment section movable with said driving member, and a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving member so as to prevent rebounding thereof.

5. In an engine starting device, a drive shaft unit, an engine driving member on said unit adapted for both longitudinal and rotary movement, said member including an axially extending portion providing a housing and adapted in one shifted position to operatively engage an engine gear to be driven, a-coiled spring structureon said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said driving member, and a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradual building up of frictional resistancebetween said coiled spring and actuating means during the final relativerotation between said coiled springand actuating means, and thereby gradually decelerate said engine driving member so as to prevent rebounding thereof.

6. In an engine starting device, a drive shaft unit, an engine driving member on said unit adapted for both longitudinal and rotary movement, said member including an axially extending portion providing a housing and adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said driving member, and a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving member so as to prevent rebounding thereof, said abutment sections being positioned within said housing.

7. In an engine starting device, a drive shaft unit, an engine driving member on said unit adapted for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said driving member, a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving memher so as to prevent rebounding thereof, and resilient means acting between the structure of said drive shaft unit and engine driving member to maintain frictional contact between said aotuating means and spring.

8. In an engine starting device, a drive shaft unit including a motor shaft and interlocked sleeve elements, an engine driving member on said unit adapted for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said driving member, and a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving member so as to; prevent rebounding thereof.

9. In an engine starting device, a drive shaft unit, an engine driving member on said unit 1 adapted for both longitudinal and rotarymovement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, said coiled spring structure including a double strand of wire providing a loop at one extremity, the'opposite free extremities of said strands being coupled with said engine driving member, actuating means movable with said drive shaft unit and cooperating said said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said driving member, and a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate-said engine driving member so as to prevent rebound thereof.

10. In an engine starting device, a drive shaft unit, an en ine driving memberon said unit adapted for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said:

driving member, a second abutment section associated with said drive shaft unitadapted to be friction ally engaged by the first abutment section when said driving member is being retracted whereby to cause relative gradualbuilding up of frictional resistance between said coiledspring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving member so as to prevent rebounding thereof, and means for positively limiting the retracting rotation of the engine driving member. 11. In an engine startingdevice, a drive shaft unit, an engine driving member on said unit adapted for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section'movable with said driving member, a second abutment section associated with said drive shaft unit adapted to be frictionally engaged by the first abutment section when saiddriving member is being retracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving member so as to prevent rebounding thereof, and means for limiting the amount of rotative frictional resistance which may be built up between said spring and actuating means.

12. In an engine starting device, a drive shaft unit, an engine driving member on said unit adapted for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine gear to be driven, a coiled spring structure on said unit and movable with said driving member, actuating means movable with said drive shaft unit and cooperating with said coiled spring for effecting longitudinal movement of said engine driving member, an abutment section movable with said driving member and having an abutment surface positioned in a plane substantially perpendicular to the axis of said driving member, and a second abutment section associated with said drive shaft unit having an abutment surface lying in a plane substantially perpendicular to the axis of said driving member and adapted to be frictionally engaged by the surface of said first abutment section when said driving member is being re- U tracted whereby to cause relative gradual building up of frictional resistance between said coiled spring and actuating means during the final relative rotation between said coiled spring and actuating means, and thereby gradually decelerate said engine driving member so as to prevent rebounding thereof.

JAMES A. CHARTER. 

